Connector with built-in bent optical fibers and method for producing bent optical fibers

Abstract

A connector with built-in bent optical fibers includes an optical fiber array including a plurality of bent optical fibers each having a bent portion and a linear portion formed integrally with the bent portion, a ferrule having a plurality of positioning mechanisms that align end portions of the plurality of bent optical fibers, and a resin portion disposed at an outer periphery of the bent portion. The resin portion is filled in the ferrule. The bent portion has a bending angle of 85°-150°. When the bent portion of one bent optical fiber is divided into a plurality of regions along a longitudinal direction at 10°, a variation in bend radius among the plurality of regions excluding regions corresponding to 10° at both ends is 0.3 mm or less, an outer diameter of the bent portion of the bent optical fiber is smaller than an outer diameter of the linear portion.

What is claimed is: 
     
       1. A method for producing a bent optical fiber obtained by performing a bending process on a silica optical fiber, the method comprising:
 bending the optical fiber along a contour of the heater by pressing the optical fiber against a heater having an arbitrary shape; and 
 removing a defect in an inner surface of a bent portion of the bent optical fiber,
 wherein removing includes heating the inner surface using a non-contact heat source while adjusting a bending angle of the bent optical fiber to be a predetermined angle. 
 
 
     
     
       2. The method for producing the bent optical fiber according to  claim 1 , further comprising, cooling the bent optical fiber before removing the defect. 
     
     
       3. The method for producing the bent optical fiber according to  claim 1 , wherein the non-contact heat source is an arc discharge. 
     
     
       4. The method for producing the bent optical fiber according to  claim 1 , wherein the non-contact heat source is laser light. 
     
     
       5. The method for producing a bent optical fiber according to  claim 1 , wherein removing includes heating the bent optical fiber with the bent optical fiber being set on a fixing tool for fixing the bent optical fiber at a predetermined angle. 
     
     
       6. The method for producing a bent optical fiber according to  claim 1 , wherein the bending includes bending the optical fiber so that a bend radius of the bent portion is less than or equal to 5 mm. 
     
     
       7. The method for producing a bent optical fiber according to  claim 1 , wherein the predetermined angle is greater than or equal to 85° but less than or equal to 150°. 
     
     
       8. The method for producing a bent optical fiber according to  claim 1 , wherein removing includes heating the bent optical fiber so that, when the bent portion of one bent optical fiber is divided into a plurality of regions along a longitudinal direction at 10°, a variation in bend radius among the plurality of regions excluding regions corresponding to 10° at both ends is less than or equal to 0.3 mm. 
     
     
       9. The method for producing a bent optical fiber according to  claim 1 , wherein removing includes heating the bent optical fiber so that the inner surface of the bent portion is a satin finished surface. 
     
     
       10. The method for producing a bent optical fiber according to  claim 1 , wherein an outer diameter of the bent portion of the bent optical fiber obtained at the removal is smaller than an outer diameter of a linear portion of the bent optical fiber. 
     
     
       11. The method for producing a bent optical fiber according to  claim 1 , wherein the number of the bent optical fibers is four or more, and a difference between the maximum angle and the minimum angle in a plurality of bent portions of all the bent optical fibers is within 2.0°. 
     
     
       12. The method for producing a bent optical fiber according to  claim 1 , wherein a cross-sectional shape of the bent portion obtained at removal is a substantially elliptical shape having a minor axis that is a direction connecting an inner surface and an outer surface of the bent portion. 
     
     
       13. The method for producing a bent optical fiber according to  claim 1 , wherein a linear portion of the bent optical fiber has an outer diameter of 80 μm to 126 μm. 
     
     
       14. The method for producing a bent optical fiber according to  claim 1 , wherein a linear portion of the bent optical fiber has an outer diameter of preferably 124 μm to 126 μm, and the bent portion per bent optical fiber has a strength of greater than or equal to 0.25 N. 
     
     
       15. A method for producing a connector with built-in bent optical fibers, the method comprising:
 bending the optical fiber along a contour of the heater by pressing a silica optical fiber against a heater having an arbitrary shape; 
 removing a defect in an inner surface of a bent portion of the bent optical fiber; 
 forming an optical fiber array including the plurality of bent optical fibers produced by the removing; 
 arranging end portions of the plurality of bent optical fibers at a plurality of positioning mechanisms in a ferrule to accommodate the optical fiber array in the ferrule; and 
 filling resin in the ferrule on an outer periphery of the bent portions, 
 wherein removing includes heating the inner surface using a non-contact heat source while adjusting a bending angle of the bent optical fiber to be a predetermined angle.